Twochanges relating to the new DOM bindings caused the smaller regression on December 11/12. This is largely because many more JS getter/setter functions are present. It’s not clear yet how to win back this memory, though it should be possible to turn these changes off in the short-term.

These regressions have made it to the Aurora branch, which means there is some urgency now to either fix them or back out/disable them soon. We don’t want them to reach Beta.

Bug Counts

Here are the current bug counts.

P1: 21 (-1/+7)

P2: 125 (-2/+11)

P3: 104 (-1/+3)

Unprioritized: 4 (-17/+3)

The changes are larger than usual because we had a big log of untriaged bugs to go through, due to the six week break since the last MemShrink meeting.

What’s not clear is what, if anything, to do about it in the short term. Turning the quickstubs off is highly undesirable in general, since it leads to the same method/property behaving differently on different HTML elements.

If I had to take a shot in the dark; I’d assume it’s part of the additional record keeping needed to create a generational/compacting garbage collector, but that’s only because I’m not aware of any other major JS projects currently in progress.